Working men earning more than £40,000 a year are responsible for the lion's share of climate change emissions from personal travel, according to a Oxford University survey. It found that one in five people are responsible for 61% of climate change emissions from private transport and that most of these are well-off men.

Christian Brand at the university's transport studies unit, who carried out the research with Brenda Boardman, said that discussions about reducing emissions usually focused on the average carbon footprint. "Our work shows there's a huge range," he said.

While most people emitted between one and three tonnes of CO2 in total through their personal travel in the previous year, the top 10% had an average of 19.2 tonnes of CO2 from flying alone. The data came from a survey of leisure travel using all modes of transport by 456 people at 278 addresses in Oxfordshire.

The survey points to aviation as the biggest single source of emissions, closely followed by car use. The impact from air travel on global warming is higher than its carbon emissions alone because gases and water vapour are released at altitude. Taking this effect into account, the team calculated that aviation's share of climate impact is 70.4%. "Air travel is so cheap - mainly because there is hardly any tax paid on it - that people start thinking of that as their first mode of transport when it comes to leisure travel," said Dr Brand.

Tony Juniper, of Friends of the Earth, said: "Finding ways in which the message can be got through to the people with the biggest carbon footprint would be a way of getting some easy wins. That needs to be reflected in policy, for example changing the way in which vehicle excise duty is levied to discourage people from buying big gas guzzlers and putting more of a signal into the price of a flight ticket."

The danger was that even if large numbers of people changed their behaviour a small minority could blow targets out of the water. Peter Cox, a climate expert at Exeter University, believes the rich would be able to buy themselves higher emissions. "Putting a tax on a unit of carbon wouldn't hit them particularly hard."